From fd2aeac5606f8c706be5e07bead790c6cdee0f23 Mon Sep 17 00:00:00 2001 From: Manfred Huber Date: Fri, 29 Mar 2013 02:52:36 +0000 Subject: omap3_beagle: Flush UART3 xmit on enable if TEMT is broken MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Flush UART3 xmit on enable if TEMT is broken On some OMAP3 devices when UART3 is configured for boot mode before SPL starts only THRE bit is set. We have to empty the transmitter before initialization starts. This patch avoids the use of CONFIG_SYS_NS16550_BROKEN_TEMT. Signed-off-by: Manfred Huber Tested-by: Javier Martinez Canillas Tested-by: Andreas Bießmann --- drivers/serial/ns16550.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'drivers/serial/ns16550.c') diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c index ed4e6b3..7f013ab 100644 --- a/drivers/serial/ns16550.c +++ b/drivers/serial/ns16550.c @@ -36,10 +36,24 @@ void NS16550_init(NS16550_t com_port, int baud_divisor) { -#if (!defined(CONFIG_SYS_NS16550_BROKEN_TEMT)) +#if (defined(CONFIG_SPL_BUILD) && defined(CONFIG_OMAP34XX)) + /* + * On some OMAP3 devices when UART3 is configured for boot mode before + * SPL starts only THRE bit is set. We have to empty the transmitter + * before initialization starts. + */ + if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE)) + == UART_LSR_THRE) { + serial_out(UART_LCR_DLAB, &com_port->lcr); + serial_out(baud_divisor & 0xff, &com_port->dll); + serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm); + serial_out(UART_LCRVAL, &com_port->lcr); + serial_out(0, &com_port->mdr1); + } +#endif + while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT)) ; -#endif serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier); #if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \ -- cgit v1.1